Molybdenum oxysulfide dithiocarbamates and processes for their preparation



United States atent 3,356,702 MOLYBDENUM OXYSULFIDE DITHIOCARBA- MATESAND PROCESSES FOR THEIR PREP- ARATION Homer H. Farmer, Westport, andEugene V. Rowan,

Rowayton, Conn., assignors to R. T. Vanderbilt Company, Inc., New York,N.Y., a corporation of New York Filed Aug. 7, 1964, Ser. No. 388,110 11Claims. (Cl. 260-429) This invention relates to a new composition ofmatter useful as an extreme pressure agent, antioxidant and'wearinhibitor for lubricants, and in particular to dialkyldithiocarbamatesof molybdenum.

Compounds considered, on the basis of elemental analysis, to correspondto the general formula have been reported by Malatesta (Gaz. Chim.Ital., 69, 752-62 (1939)) to form when an alkaline mixture of a solublemolybdate and a soluble dithiocarbamate are treated with a dilute acid.Yellow MoO (HSC-SNEt was reported by Kulberg et al. (Doklady Akad. Nauk.S.S.S.R., 98, 79-81 (1954)) to form when concentrated aqueous ammoniummolybdate reacts with sodium diethyldithiocarbamate in neutral or weaklyacidic medium, but when the molybdate was first warmed to 6070 C. andthen strongly acidified with N hydrochloric acid, a product having thesame elementary composition but a red-violet color and givingqualitative tests for both- Mo(III) and Mo (V) was formed.

It has now been discovered, in accordance with the present invention,that a new class of dithiocarbamates can be prepared which containsoxygen and more sulfur than can be attributed to the dithiocarbamategroups alone, thus differing from the molybdenum dithiocarbamates of theprior art. The new compounds are yellow in color, crystalline, fusible,and they have many of the indicia of pure compounds. While differentpreparations of the same compound vary slightly in elemental analysis,their infrared spectra are essentially identical and their meltingpoints fall within the same narrow range. The proportions of oxygen andsulfur also fall within a restricted and definite range.

It has been found that the general formula of the compounds varies fromthat is within the framework of the general formula MO O S where m+n=4,m is in the range 2.35 to 3 and n is in the range 1.65 to 1, and R is anunsubstituted hydrocarbon group having 1 to 24 carbon atoms. In general,the group R is defined as being an unsubstituted hydrocarbon group (suchas alkyl or alkenyl) of any of the secondary amines (R-NHR) that willreact with carbon disulfide to form dithiocarbamates. Such amines arewell known in the prior art.

In the compound in which R is G l-l (normal bu'tyl) the final producthas a very narrow melting range, that is 254258 C. and it cannot beseparated into components by thin layer chromatography. Although theanalytical result do not fit exactly the formula of any singledithiocarbamate, the results show that there is always onedithiocarbamate residue per molybdenum atom and that the molybdenum hasan elfective valence of 5. It is not known whether each ofthe-twomolybdenum atoms present in the sulfurized dithiocarbamate molecule hasa valence of or one has a valence of 4 and the other 6.

3,356,702 Patented Dec. 5, 1967 The sulfurized molybdenumdialkyldithiocarbamates correspond to a mixture which might possibly berepresented by:

be separated into individual components by the techniques of thin layerchromatography.

FIGURE 1 is the infrared absorption spectrum of sulfurized molybdenumdibutyldithiocarbamate prepared by the procedure of Example 1, using theNujol' mull technique and a Perkin-Elmer double beam spectrophotometer.Sulfurized molybdenum dibutyldithiocarbamate absorbs strongly at 3.5(Nujol), 6.55, 6.85 (Nujol), 7.30 (Nujol) and 10.35microns; moderatelyat 7.75, 8.20 and 10.50 (shoulder) microns; andweakly at 8.50, 8.75,9.05, 9.20, 13.85 and 14.15 microns.

The sulfurized-molybdenum dialkyldithiocarbamates of the invention canbe prepared by two different general procedures. In one proceduremolybdic oxide M00 is converted to soluble molybdate by dissolving it inan alkali metal hydroxide solution or in ammonium hydroxide, andfiltering to remove any impurities present if crude M00 is used as thesource of molybdenum. The molybdate solution is neutralized to litmus bythe addition of acid, then the secondary amine and carbon disulfide areadded, and the mixture is heated.

In the second method, pure, solid M00 or M00 is placed in a polarsolvent and the secondary amine and carbon disulfide are added. In someinstances, the secondary amine itself may serve as the polar solvent.More detailed directions for preparing the sulfurized molybdenumdialkyldithiocarbamates of the invention are presented in the examples.

In the rocedure of the prior art it has been observed that a reddish orred product is first formed at room temperature when either the metaloxide or the metal salt is reacted with the carbon disulfide and asecondary amine. This first or intermediate product is probably aconventional dithiocarbamate, as shown by its infrared spectrum, thatis, the intermediate product shows the characteristic single absorptionband at 10.35;; associated with the conventional dithiocarbamategrouping of atoms. In accordance with the process of the presentinvention, however, the reaction mixture is heated at a temperature inexcess of C. and preferably above C. to bring about the formation of theproduct of the present invention. Under these conditions it is believedthat the substitution of an oxygen in the molybdenum-oxygen moiety bysulfur takes place. The substitution reaction takes place more readilywhen an excess of carbon disulfide (over that necessary to formconventional dithiocarbamates) is present.

The time during which the desired elevated temperature is maintainedprobably depends on both the nature of the secondary amine (orconventional dithiocarbamate probably formed as an intermediate) and thepot temperature of the reaction mixture. In the preparation ofsulfurized molybdenum dibutyldithiocarbamate, the heating time given inthe examples ranges from 2 hours when the eaction was carried out inbutanol, 3.5 hours in dimethyl ormamide, to 5.5 hours when carried outin water. The iethyl derivative has been made in 2 hours, the diamylerivative in 3 hours, and the dilauryl derivative in 6 LOUIS.

The preferred ratio of carbon disulfid to molybdenum o amine is 2:1:1.5as reported in Run No. 1 of the ollowing table. A procedure in which theratio of amine o molybdenum was kept at 1.511 while that of carbonlisulfide to molybdenum was reduced to 1:1 is reported as Run No. 2 inthe table. This was carried out by the odium molybdat method. Thereaction was carried out or 1.5 hours rather than the period of hoursused in be other examples described hereinafter. The yield of rudeproduct was 31%. A sample was recrystallized rom dimethyl formamide foranalysis. In Run No. 3 he ratio of carbon disulfide to molybdenum waskept at [:1 and that of the amine to molybdenum was raised 0 2:1. Thereactants themselves were the solvents in this 'eaction. Again ananalytical sample was recrystallized from dirnethyl formamide. The yieldwas 72% of theoretcal.

as solvent were placed in a 3-necked, l-litcr flask equipped withstirrer, thermometer and reflux condenser, and cooled to below C. Carbondisulfide (1 mole, 76 grams) was dropped into the mixture with cooling;after the addition, the mixture was stirred for 30 minutes at roomtemperature, then refluxed for two hours at a pot temperature of aboutl05110 C. Although pure butanol boils at 118 C., the lower pottemperature was due to the presence of the CS The pot temperature ros asthe CS was consumed. The reaction mixture was filtered while hot, thefilter cake washed with methanol, and dried to yield 166 grams of ayellow solid which melted at 255-257 C.

Analysis (percent).Mo, 28.57, 29.01; S, 25.51; C, 31.58; H, 5.21.

EXAMPLE 3 Sulfurized molybdenum dibutyldithioearbamate from pure M00 indimethyIformamide medium Pure molybdic oxide (0.5 mole, 72 grams),dibutylamine (0.75 mole, 97.2 grams), and dimethylformamide VARIATION OFYIELD OF SULFURIZED MOLYBDENUM DIALKYLDITHIOCARBAMATE WITH RATIO OFREACTANTS Analysis Run N0. Ratio Yield, M.P., C.

os zMozBuzNli Percent S N O H The infrared spectra of the three productsare essentially identical, that is the same functional groups andlinkages are present in all. of them. It is concluded that a change inratio of reactants results in decreasing yield but no demonstrabledifference in the product itself.

As polar solvents for the reaction, pyridine di-methylformamide,alcohols such as butanol and hexanol may be used. A more completedefinition of the term will be found in Concise Chemical and TechnicalDictionary Second Enlarged Edition, edited by H. Bennett and publishedin New York by Chemical Publishing Co., 1962, at page 743.

The following examples illustrate how the invention may be practiced.

EXAMPLE 1 Sulfurized molybdenum dibutyldithiocarbamate from crude M00Crude molybdic oxide (M00 90%, 0.5 mole, 80.1 grams) was slurried in 150ml. water and treated with sodium hydroxide solution (0.437 mole, 35grams of 50% solution), stirred for 30 minutes, and neutralized tolitmus with 50% sulfuric acid. Filtration yielded 8 grams of residue,the impurities from the crude M00 The filtrate Was placed in a 3-necked,l-liter flask equipped with stirrer, thermometer and reflux condenser,and dibutylamine (0.75 mole, 97.2 grams) was added. Carbon disulfide (1mole, 76 grams) was added dropwise to the mixture. The reaction mixturewas refluxed for 5.5 hours at a pot temperature of 104 C., filtered, thefilter cake washed with water and then with toluene to yield a yellowsolid melting at 254-25 6 C.

Analysis (percent).-Mo, 28.70; S, 25.77; C, 31.42; H, 5.44; N, 4.10.

EXAMPLE 2 S'ulfurized molybdenum dibutyldithiacarbamate from pure M00 inbutanol medium Pure molybdic oxide (0.5 mole, 72 grams), dibutylamine(0.75 mole, 97.2 grams) and butanol (100ml) ml.) as solvent were placedin a 3-necked, l-liter flask equipped with stirrer, thermometer andreflux condenser, and cooled below 30 C. Carbon disulfide (0.75 mole, 57grams) was added to the mixture dropwise, with cooling. After additionwas complete, the reaction mixture was stirred for one hour at roomtemperature, then heated at C. for 1.5 hours. Carbon disulfide (0.25mole, 19 grams) was added to the reaction mixture dropwise with stirringand the reaction continued for an additional two hours at 105 C., thenthe flask was cooled and the contents filtered. The filter cake waswashed with methanol and dried, yielding grams of a yellow solid whichmelted at 255257 C. (recrystallized from dimethylformamide) EXAMPLE 4Sulfurized molybdenum diezhyldithiocarbamate from pure M00 indimethylformamide medium Diethylamine (0.75 mole, 54.8 grams) wassubstituted for the dibutylamine in the procedure of Example 3. Thereaction mixture was stirred for 30 minutes at room temperature, thenheated at 105 C. for two hours, cooled, and filtered. The filter cakewas washed with methanol and dried. A yellow solid melting above 300 C.was obtained in 142 gram yield.

Analysis (percent).-S, 33.19; C, 20.86; H, 3.75; N, 4.84.

EXAMPLE 5 Sulfurized molybdenum diethyldithiocarbamate from M00 indimethylformamide medium The procedure of Example 4 was followed,substituting M00 (0.5 mole, 64 grams) for the M00 The yield was smallerthan that obtained with M00 and it contained unreacted M00 but theinfrared spectrum of the purified product was identical with that of theproduct of Example 4 in which M00 was the source of molybdenum.

EXAMPLE 6 Sulfurized molybdenum diamyldithiocarbamate, no added solventPure molybdic oxide (1.0 mole, 143 grams) and diamylamine (2.0 moles,314 grams) were placed in a 3- necked, 2-liter flask equipped withstirrer, thermometer and reflux condenser. The mixture was heated tobetween 120 and 150 C. with stirring while carbon disulfide (2.0 moles,152 grams) was added dropwise. The reaction mixture was heated andstirred for 3 hours after carbon disulfide addition was complete, thenfiltered. The residue was slurried with methanol and filtered again,yielding 342 grams of olive green solid. When purified by washing withacetone, the product was yellow and melted at 205- 211 C.

EXAMPLE 7 Sulfurized molybdenum dilauryldithiocarbamale in hexanolmedium Pure molybdic oxide (0.5 mole, 72 grams), dilaurylamine (0.75mole, 190.2 grams) and hexanol (300 ml.) were placed in a S-necked,l-liter flask equipped with stirrer, thermometer and reflux condenser,then carbon disulfide (0.75 mole, 57 grams) was added dropwise whilecooling. After addition was complete, the reaction mixture was stirredfor 15 minutes at room temperature, then refluxed for 6 hours, cooled,and filtered. The solid product was slurried with ammonium hydroxide andfiltered to yield 225 grams of yellow solid.

Infrared absorption spectra were determined in the compounds prepared inthe foregoing examples. Infrared absorption bands are located as shownin the following table.

EXAMPLE 8 Sulfurized molybdenum di(.oleyl-lin0leyl) dithiocarbamate frompure M00 in amyl alcohol solvent Pure molybdic oxide (0.5 mole, 72grams) di(tall oil) secondary amine (Alamine 215 of General Mills) (0.75mole, 390 grams), and amyl alcohol (20 ml.) as reaction medium, wereplaced in a 3-necked, l-liter flask equipped with stirrer, thermometerand reflux condenser. Carbon disulfide (1.0 mole, 76 grams) was addeddropwise to the mixture. After addition was complete, the reactionmixture was heated for two hours at 110 C., then the solvent wasdistilled at 145 C. The reaction product was cooled, slurried inmethanol and filtered to obtain a crude product. Alamine 215, thesecondary amine used in the synthesis, is a mixture of secondary aminesderived from the mixture of amines obtained from tall oil fatty acidsand containing predominantly the oleyl and linoleyl groups in nearlyequal proportions.

In the following examples the sulfurized dithiocarbamates of theinvention were tested for their effectiveness as extreme pressureagents, wear inhibitors, and antioxidants in various lubricatingcompositions. The preferred method of incorporating the additive in thecomposition is to pass the mixture three times through a three rollmill.

EXAMPLE 9 To separate portions of a lithium 12-hydroxy-stearate grease(containing a rust inhibitor as its only additive) was added asulfurized molybdenum dialkyldithiocarba- DIALKYLDIIHIOCARBAMATE DiethylDibutyl Diamyl Dilauryl 3.5 doublet 3.5 doublet 3.5 doublet 3.2 doublet(Nujol). 6.5 strong 6.55 strong 6.5 strong {2: f&%%%; 6.85 6.85(NlljOl). 6.9 M shoulder 7 95 7.20 weak.

-- 7.25 (Nmol).

7.4 moderate 7.8 M doublet 7.75 1 l M }s.0 weak. 8.35 ML--. 8.2 8.25 M8.15 W.

8.5 18.55 W {8.75 Wfdoublet (8.75 3%? gkoublet {3:3 g doublet 10.35 S10.35 S 10.35 5 10.35 51 10.5 M dmblet {10.5 M shoulden 10.5 ivrl {10.45Mj 11.0 W 11.85 W 1 12.90 W

13.85 L 13.6 13.85 \V. 14.1 W 14.15 W 14.1 W

Legend: S=strong, M=moderate, W=weak.

Strong bands near 3.5, 6.85 and 7.25 are those due to the C-C and CHlinkages of the hydrocarbon, Nujol, plus the effect of the hydrocarbonlinkages in the alkyl groups of the dithiocarbamates, hence theirintensity is not significant and has not been indicated. It will benoted that the 10.35, band characteristic of the mate in varyingproportions. Sulfurized di-n-butyl, di-namyl anddilauryldithiocarbamates were used at 3% concentration based on theweight of the grease composition, and the dilauryl compound was alsotested at 6%. Another sample containing no sulfurized molybdenumdialkyldithiocarbamate served as untreated control.

The compositions so produced were subjected to the Timken Endurance Testin the Timken Lubricant Tester in which a hardened steel ring rotatingat 800 r.p.m. is smeared with 0.5 gram of the test grease while ahardened steel block is pressed against it by a system of weights andlevers. A ten-pound load was used, and the test was run for a maximum of8 hours, or until the bearing seized. The time to failure was recordedin hours and minutes.

TIMKEN TESTS IN GREASE .lkyl Group Control Dibutyl Diamyl DilaurylDilauryl ercent in grease. 3 3 3 6 )uration in hrs.:min. 0:01 :20 3:200:01 2:30

EXAMPLE The compositions of Examples 8 and 9 as well as sulfurzedmolybdenum dibutyldithiocarbamate at 1%, and the liethyl derivative at3% concentration were subjected to he Falex Wear Test. The compositionfrom Example 8 Ithe oleyl-linoleyl compound) is the crude product. Inthe Falex Wear Test, a At-inch diameter steel rod is rotated it 290r.p.m. between two steel V-blocks at a gauge load )f 350 pounds. Thetest grease is smeared over the V- JlOCkS, and the load is appliedgradually over the first minute. The test is run for one hour maximum,or until :he bearing seizes. Wear is determined by weighing the pin andthe blocks to the nearest 0.2 mg. before and after the test, and theloss in weight is recorded. Friction is registered continuously on aBourdon-type gauge and is recorded in inch-pounds in the table below.

FALEX WEAR TESTS SHELL t'BALL TESTS IN GREASE Control, With 3% 5 NoDibutyl Additive Additive Wear Test, 2 hours maximum, 1,800

r.p.m., IO-kg. load:

Wear scar diam., mm 1. 01 0.38 Pressure at this diam., p.s.i 29, 300200,000 10 Temperature rise, F 76 42 Extreme Pressure Test, one minute:

Weld load, kg 126 251 EXAMPLE 12 The Norma-Hoflman test, ASTM D-94250,was applied to all of the compositions of Example 10 except thatcontaining 1% sulfurized molybdenum dibutyldithiocarbamate. Timerequired to produce a 25-pound pressure drop from 110 psi. was recorded.

Greases containing sulfurized molybdenum dialkyldithiocarbamates of 4 or5 carbon atoms per alkyl group at 3% concentration have good antiwearproperties, while the dilauryl derivative having double thatconcentration also showed good wear characteristics.

EXAMPLE 1 1 Samples of base grease and grease containing 3% sulfurizedmolybdenum dibutyldithiocarbamate were tested in the Shell 4-BallMachine, in which a /2-inch steel ball is rotated in contact with threesimilar balls which are clamped in a stationary position so as toprovide three points of contact. In the wear test, a pressure of kg. isapplied to the ball, rotating at 1800' r.p.m., for two hours.Temperature rise is noted, and the diameter of the wear scar is measuredand the pressure on this spot is calculated. In the extreme pressuretest using the same equipment, increasing loads are applied for .oneminute each to the rotating ball, and the load at which the balls weldtogether is recorded. The results of these tests are summarized in thetable below.

NO EMA-HOFFMAN BOMB-OXIDATION TEST Alkyl Group Percent in Hours to25-11). Grease Pressure Drop Control 0 190 Diethyl. 3 848, 984 DibutyL 3780, 672 D amyl. 3 780, 780 Dilauryl 3 864, 1, 272

Thus it is shown that the sulfurized molybdenum dialkyldithiocarbamatesnot only protect uninhibited grease from oxidation, but that the dibutyland the diarnyl com pounds at 3% concentration exert a surprisinglyefiective and dependable antiwear eifect, the dibutyl compound havingthe better Timken Endurance Test.

EXAMPLE 13 The sulfurized molybdenum dibutyldithiocarbamate of 5 theinvention was compared with molybdenum disulfide,

a well known solid lubricant widely used as an additive in lubricatinggreases. MoS- was incorporated into the lithium 12-hydroxystearategrease of Example 9 in concentrations of 2% and 3%, and the greasessubjected to 0 the Timken Endurance Test of Example 9, the Falex WearTest of Example 10 and the Norma-Hoffman Bomb Oxidation Test of Example12. The table below compares these values with those obtained using 2%and 3% sultfurized molybdenum dibutyldithiocarbamate greases and 5 thebase grease.

COMPARISON OF SULFURIZED MOLYBDENUM DIBUTYLDI'IHIOCARBAMATE WITHMOLYBDENUM DISULFIDE Additive at 2% Additive at 3% Test No AdditiveMo-di-Bu-DTO MOS: Mo-di-Bu-DTC MoSz Timken Endurance Test,

IO-lb. Load: Duration, hrs.:minutes :01 5:00 0z01 Falex Wear Test,

350-1b. Load, Maximum 1 hr.:

Duration, minutes 2. 5 60 I 60 60 60 Pin Wt. Loss, mg 0.1 0.5 0.8 0.8Block Wt. Loss, mg 2. O 2. 2 1.8 1. 6 Friction, in.-lb 6 l1 8 8Norma-Hoflman Bomb Oxidation Test:

Pressure Drop in 100 hrs., 1b 7. 8 6-8 6 40 Time to 25-lb. PressureDrop, hrs 190 600 876 48 1 Only 1 run in 3 lasted 60 minutes.

These data show that sulfunzed molybdenum dibutyl- We claim:

dithiocarbamate is vastly superior to molybdenum disulfide in equalconcentration (3% each in the Timken Endurance Test). It is the equal ofmolybdenum disulfide at 3% in the Falex Wear Test and may exceedmolybdenum disulfide at the 2% level of each, while in the Norma-Hoffmantest, 3% of the sulfurized dithiocarbamate far surpasses molybdenumdisulfide in antioxidant effect.

EXAMPLE 14 Diester base grease (bis(2-cthylhexyl) sebacate thickenedwith lithium 12-hydroxystearate) and the same grease containing 3% byweight of sulfurized molybdenum dibutyldithiocarbamate were submitted tothe 4-Ball Wear Test of Example 11, using two diiferent test loads. Thefollowing table reports the results of these tests as the average of thevertical and horizontal dimensions of the wear scars on all three balls:

Sulfurized molybdenum Load, Diameter of Wear dibutyldithiocarbamate kg.Scar Average, mm.

concentration, percent 0 40 Fail These data show that sulfurizedmolybdenum dibutyldithiocarbamate is an excellent antiwear agent indiester base, lithium soap greases.

EXAMPLE 15 The Norma-Hoffman Oxidation Test was applied to the diesterbase greases of Example 14. The table below compares the rate ofoxidation as measured by oxygen pressure drop of grease containing 3% byweight of sulfurized molybdenum dibutyldithiocarbamate with that of thebase grease:

Sulfurized molyb- Pressure Drop in- Time to denum dibutyldithiofi-lb.Drop, carbamate concentrahrs.

tion, percent 100 hrs. 500 hrs.

Sulfurized molybdenum dibutyldithiocarbamate is thus shown to be anexcellent oxidation inhibitor in diester base grease.

1. A compound having the general formula [R2N-CSS] MO2O n where m+n'=4,m is in the range 2.35 to 3 and n is in the range 1.65 to l, and R is ahydrocarbon group having 1-24 carbon atoms such that the compound willreact with carbon disulfide to form a dithiocarbamate.

2. The compound described in claim 1 in which the group R is butyl andhaving an infrared absorption spectrum as shown in FIGURE 1.

3. The process of preparing the compound described in claim 1 whichcomprises mixing and reacting together in a polar organic solvent carbondisulfide, molybdic oxide and a secondary amine, RgNH which is capableof forming a conventional dithiocarbamate with CS and such that R is ahydrocarbon group having from 1 to 24 carbon atoms, and maintaining saidmixture at a temperature above 90 C. for a time sufiicient to cause theformation of said compound.

4. The process of claim 3 wherein said group R is butyl.

5. The process of preparing the compound described in claim 1 whichcomprises mixing and reacting in aqueous solution, neutralized solublemolybdate selected from the class consisting of alkali metal molybdatesand ammonium molybdate, with carbon disulfide and a secondary amine, RNH which is capable of forming a conventional dithiocarbamate with CSand R is a hydrocarbon group having 1 to 24 carbon atoms, andmaintaining said mixture above 90 C. for a time suflicient to cause theformation of said compound.

6. The process of claim 3 in which the molar ratio of carbon disulfideto molybdic oxide to secondary amine is about 2:1:1.5.

7. The process of claim 5 in which the molar ratio of carbon disulfideto soluble molybdate to secondary amine is about 2:1:1.5.

8. The compound described in claim 1 in which the group R is ethyl.

9. The compound described in claim 1 in which the group R is amyl.

10. The compound described in claim 1 in which the group R is lauryl.

11. The compound described in claim 1 in which the group R isoleyl-linoleyl, said compound having been derived from di(tall oil)amine.

No references cited.

TOBIAS E. LEVOW, Primary Examiner.

A. P. DEMERS, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,356,702 December 5 1967 Homer H. Farmer et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 2, lines 9 to 12, for that portion of the formula reading M0 M0read M0 M0 T O '5' T O a:

Signed and sealed this 18th day of February 1969.

SEAL) kttest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER \ttesting Officer Commissionerof Patents

1. A COMPOUND HAVING THE GENERAL FORMULA